Nevada expert wants to help alfalfa farmers reduce water use as debate over thirsty crop grows
On a chilly, overcast day in Reno, Alejandro Andrade-Rodriguez walked across a tiny field surrounded by city streets and single-family homes.
This is a test field used by the University of Nevada, Reno, and Andrade-Rodriguez, an agriculture professor, is working his way toward an irrigation pivot that stretches 140 feet across the field.
As crops crunched under his shoes, Andrade-Rodriguez pointed at the low-elevation sprinklers, equipped with sensors he developed, that dangled above green alfalfa.
“With those sensors, we monitor how much water is being consumed by the crop, and we also determine how much water we need to provide to the soil,” he said.
Traditional irrigation pivots spray every part of a field with the same amount of water. However, farmland can have different soil types and elevations.
“You may have in a certain part of the field, one soil that retains more water for a longer time,” he added.
The sensors, and accompanying software, allow farmers to see, in real time, when to alter the amount of water they’re spraying, a technique called precision irrigation management.
Andrade-Rodriguez didn’t water this alfalfa on this wintery day – that’ll happen come spring.
“If we have, right now, the irrigation system running, pipes freeze and it will be no good whatsoever,” he said with a laugh.
Andrade-Rodriguez is leading the university’s role in a three-year project receiving nearly $750,000 from the U.S. Department of Agriculture (USDA). The federal agency’s research center in Texas is testing the technology on cotton, and the University of California-Davis is using it on corn.
“It’s trying to reduce the amount of water that is used right now, while still helping to produce that food in an inexpensive way and an affordable way,” Andrade-Rodriguez said.
Conservationists argue many farming areas use water faster than it can be replenished by winter storms. Take Northern Nevada’s Walker River Basin, which is blanketed with alfalfa fields, and where water supplies have been drying up for decades.
“I’m very skeptical of proposed solutions that don’t involve permanent changes in the amount of water we’re using to grow grass in the desert,” said Peter Stanton, executive director of the Walker Basin Conservancy, who pointed out the amount of water available fluctuates due to climate change. “We have seen just dramatic changes in how wet the wet years are, and how dry the dry years are.”
Another issue: close to 20% of alfalfa produced in the West was shipped overseas in 2022, according to an industry analysis of USDA data. Moreover, 11% of beef produced in the U.S. was exported in 2021, federal data shows.
“We’re literally then exporting water,” said Anne Schechinger, an agricultural economist for the nonpartisan Environmental Working Group. “It’s true, this water is being used to grow alfalfa so that people can have hamburgers. But there’s so much more water going to alfalfa in the West than people drink and use in their house. At what cost are we willing to have burgers every day?”
Agriculture leaders say many Western farms would struggle to stay in business if they stopped growing alfalfa.
That’s the case in Nevada, said J.J. Goicoechea, director of the Nevada Department of Agriculture.
“There’s a lot of soil in Nevada that won’t grow anything else,” he said. “Some of these areas you can't grow produce – you got a really narrow window as far as the growing season goes.”
There are more than 790,000 acres of irrigated farmland in Nevada, according to the USDA’s most recent Census of Agriculture in 2017. Nearly half of that acreage is planted with alfalfa, the state’s top cash crop. In 2022, production of it raked in $385 million for farmers.
“Some of these rural counties, they would not be economically whole if it was not for hay and predominantly alfalfa production,” Goicoechea said.
Back at the test field in Reno, Andrade-Rodriguez said farmers irrigating alfalfa – and other water-intensive crops – play a crucial role in the global food system. Cutting back irrigation drastically would have big consequences, he warned.
“We would have to find a way to import that food or produce that food using much less water,” he said. “And we don’t have that right now.”
Andrade-Rodriguez’s sensors and software aim to change that. The agriculture professor hopes to make the technology free for farmers to use, and the research team would hold workshops to teach them how.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNR in Nevada, KUNC in Colorado and KANW in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.
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